Canon SX740 HS has a
21.0MP 1/2.3 (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features DIGIC 8 processor. On the other hand, Panasonic ZS45 has a
16.0MP 1/2.33 (6.08 x 4.56 mm ) sized CMOS sensor .
Canon SX740 HS's sensor provides 5MP more than Panasonic ZS45's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the SX740 HS and ZS45 sensor size comparison.
Canon SX740 HS and Panasonic ZS45 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.